This second update of the original document integrates the experience of maintaining safe and sufficient supply of substances of human origin (SoHO) gained in the course of the COVID-19 pandemic and through recent scientific developments in understanding the evolution of the disease.

This first update of the original guide was prompted by the evolution of the Zika virus epidemic, a new classification system for countries/areas, and recent scientific developments.

This document includes key elements to be considered in the risk-based decision-making process of mitigating the threats to the safety of substances of human origin posed by Zika virus.

This technical report assesses the risk of Ebola virus transmission through substances of human origin and offers guidelines on the safety of donations where the potential donors are travellers returning from Ebola-affected countries, people exposed to Ebola virus or patients who have recovered from the disease.

This report summarises the discussion and outcomes of an expert consultation on communicable diseases transmissible through substances of human origin (SoHO) which took place at the European Centre for Disease Prevention and Control (ECDC) in Stockholm, Sweden, on 20 and 21 September 2011.